Simulated Prediction of Roof Water Breakout for High-Intensity Mining under Reservoirs in Mining Areas in Western China

Abstract

China is rich in coal resources under water bodies. However, the safety prediction of high-intensity mining under water bodies has long been one of the problems encountered by the coal industry. It is of great significance to realize safe mining under water bodies, improve the recovery rate of coal resources and protect reservoir resources. Therefore, this article takes the No. 5 coal seam and No. 11 mining area of the Wangwa Coal Mine as the research object, and integrates physical simulation, numerical simulation, theoretical analysis, and other methods to study the development height of water-conducting fracture zones in fully mechanized top coal caving mining. Solid–liquid coupling physical simulation tests reveal the failure characteristics of overlying strata in goaf and the seepage law of reservoir water under the influence of mining. By comparing the monitoring data of borehole leakage, the measured data obtained by borehole monitoring with the height data of the water-conducting fracture zone obtained by the traditional empirical formula of three-under standard, the error between the two is as high as −29.39%. In this case, the variance correction coefficient is used to correct the empirical formula, and on this basis, in order to effectively protect the surface water dam and water body, the mining height of the coal seam in the working face with limited height mining is inversely derived. The research results provide a basis for the safety prediction of high-intensity mining under the reservoir dam in the ecologically fragile areas of western China and a scientific guarantee for the formulation of safety measures under such conditions.

Keywords

• coal mining under reservoirs
• high-intensity mining
• green mining
• physical simulation
• water conducting fracture zone